5 papers · 1 filter
Existence of the Core in Approval-Based Committee Elections
Patrick Becker, Matthias Greger, Dominik Peters
We settle the main open question in the theory of approval-based multi-winner elections: we show that there always exists a committee in the core. The core is a stability and group…
Fractional Pareto-Optimality in Multiwinner Voting
Patrick Becker, Niclas Boehmer, Fabian Frank +1
Efficiency in multiwinner voting is most naturally captured by Pareto-optimality (PO), yet this notion is computationally and structurally difficult to handle. We therefore study f…
Core Existence in Approval-Based Committee Elections with up to Seven Voter Types
Patrick Becker, Matthias Greger, Dominik Peters
In an approval-based committee election, the task is to select a committee of up to candidates from a set of candidates based on the preferences of voters, each of whom…
On Minimal Achievable Quotas in Multiwinner Voting
Patrick Becker, Fabian Frank
Justified representation (JR) and extended justified representation (EJR) are well-established proportionality axioms in approval-based multiwinner voting. Both axioms are always s…
Efficiently Computing Equilibria in Budget-Aggregation Games
Patrick Becker, Alexander Fries, Matthias Greger +1
Budget aggregation deals with the social choice problem of distributing an exogenously given budget among a set of public projects, given agents' preferences. Taking a game-theoret…